With compromise House legislation headed by California Democrat Henry Waxman moving forward with mandatory emission limit caps on greenhouse gases, cap-and-trade appears to be leaving carbon taxes as an afterthought on Capitol Hill.

While prospects for final congressional approval and enactment into law this calendar year still remain far from certain, those advocating emissions taxes are facing even more of an uphill battle than colleagues also wanting desperately to do something … but only through cap-and-trade, and not through taxes.

The pros and cons of both approaches are neatly summarized in a May 7 posting at the Yale Environment 360 website.

Yale Environment 360 Editor Roger Cohn asked eight climate policy experts – all favoring controls, but differing on cap-and-trade versus taxes – to spell out their positions. Leaders of the Environmental Defense Fund and Natural Resources Defense Council express support for a carbon cap over a tax, while respected academics Jeffrey D. Sachs, of Columbia University’s Earth Institute, Roger A. Pielke, Jr., of the University of Colorado, prefer a tax.

For those wanting a concise source of the relative pros and cons, the exchange makes for useful … and timely … reading.

And add this into your reading assignment: New York Times reporter John M. Broder’s May 17 front-page, above-the-fold piece headlined “From a Theory to a consensus on Emissions.”

Broder’s piece sets out to answer the questions: “How did cap and trade, hatched as an academic theory in obscure economic journals half a century ago, become the policy of choice in the debate over how to slow the heating of the planet? And how did it come to eclipse the idea of simply slapping a tax on energy consumption that befouls the public square or leaves the nation hostage to foreign oil producers?”

His response is that the answer “is not to be found in the study of economics or environmental science, but in the realm where most policy debates are ultimately settled: politics.” That reality irks some remaining advocates of an emissions tax, who fear congressional leaders are opting for a short-term political situation rather than seeking a long-term climate solution.

Cap and trade, Broder wrote, “is almost perfectly designed for the buying and selling of political support through the granting of valuable emissions permits to favor specific industries and even specific congressional districts.”

Combined with the Yale E360 posting, the Broder piece makes for a productive hour of easy, and highly educational, reading.